KFPA Automatic Balance of IF path

Modification Request #? (C04 2009)

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1. Introduction

The basic observing modes for the KFPA are similar to those already used by spectral line observers. This document specifies the automatic balancing of the IF path for optimum signal levels input to the spectrometer.

2. Background

We have described KPFA pointing and focus plans for commissioning previously. The effective use of these procedures require optimum input levels to the back end and also through the fiber chain.

3. Requirements

The configuration tool will be modified so that all the IF paths (7 beams each with two polarizations) will have near optimum signal levels.

4. Design

Each amplifier in the GBT RF/IF chain has an optimum input signal level that allows accommodation of changes in the system temperature changes. An additional constraint for the 7 feed system is that two polarizations will be transmitted on a single fiber, so the RF design must accommodate this by providing similar signal levels on the two polarizations to the fiber.

5. Example Usage

The balance function has few arguments, if any.

6. Deployment Checklist

Steps in the deployment checklist.

7. Test Plan

7.1 Internal Testing

The software group must fill out this section This section covers things like unit testing, simulator testing, and any other tests required to make sure this MR is ready for sponsor/integration/regression testing.

7.2 Sponsor Testing

The sponsor testing for the balance function will be done with the input signal levels both extremely low and extremely high, to test whether the system can deduce the correct changes to the power levels.

7.3 Integration/Regression Tests

What do the integration/regression testers need to do in order to test this MR. Software Group will add this section

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Signatures

APPROVED	To the best of my knowledge, the request in this MR is complete. I have thought through this request, and believe it to be an important feature to implement or bug to fix.
ACCEPTED	I acknowledge that I have validated the completed code according to the acceptance tests.

Written	- Glen Langston - 2009 September 15
Checked	- name - date
Approved by Sponsor	- name - date
Approved by CCC	- name - date
Accepted/Delivered by Sponsor	- name - date

Symbols: Use %X% if MR is not complete (will display ) Use %Y% if MR is complete (will display )

CCC Discussion Area--

-- GlenLangston - 2009-09-15